evaluation of [68ga]ga-pentixafor pet imaging for the identification of unilateral adrenal secretion of aldosteron in patients with primary aldosteronism

Conditions: Primary Aldosteronism

Summary: pentixafor radiolabeled with 68gallium (68ga) is a radiopharmaceutical targeting the cxc chemokine receptor 4 (cxcr4) receptor. the cxcr4 receptor is expressed in zona glomerulosa of the adrenal cortex and in aldosterone producing adenoma (apa). the objective of this study will be to evaluate in 25 patients if \[68ga\]ga-pentixafor positron emission tomography (\[68ga\]ga-ptf-pet) imaging allows for the discrimination of patients with lateralized or non-lateralized secretion of aldosterone in adrenal glands classified based on adrenal vein sampling (avs).

the identification of the cause of primary aldosteronism (pa) is critical because, in case of lateralized secretion of aldosterone, a surgical treatment can be offered to patients with the objective of full patient recovery, whereas in case of bilateral secretion, only a long-term medical treatment with mineralocorticoid receptor antagonists should be considered. the presence or absence of adrenal nodule on morphological imaging does not allow us to state on the lateralization or not of aldosterone secretion. moreover, on one hand, the prevalence of adrenal incidentalomas, mostly non-secreting, can be detected in between 2 to 10% of general population. on the other hand, unilateral secretion of aldosterone exists in 30% of patients with normal adrenal glands on imaging. the avs with measurements of the concentrations of aldosterone is the closest to a referral exam to confirm the diagnosis of lateralized secretion of aldosterone, but it is a complex and invasive procedure with only limited access to centers with expertise in invasive radiology and an important heterogeneity in interpretation. the development of noninvasive imaging approaches allowing for a more specific identification of lateralized vs. bilateral aldosterone secretion would, hence, have a major impact on the clinical management of these patients.

Eligibility criteria:
inclusion criteria: * age ≥ 18 years old * signed written informed consent * french social security affiliation * for child-bearing aged women, effective form of contraception\* * diagnosis of primary aldosteronism: * with or without adrenal nodule on morphological imaging (ct or magnetic resonance imaging) * with unilateral or bilateral aldosterone secretion confirmed by invasive avs * such methods include: combined hormonal contraception, progestogen-only hormonal contraception, intrauterine device (iud) or hormone-releasing system (ius), bilateral tubal occlusion, vasectomised partner, condom, sexual abstinence. exclusion criteria: * pregnant or breastfeeding women * patient under legal protection (guardianship) * contraindication to the pet-ct * contraindication to the injection of \[68ga\]ga-pentixafor * participation in another interventional study involving human participants or being in the exclusion period at the end of a previous study involving human participants, if applicable * patient on ame (state medical aid) (unless exemption from affiliation) * completed group: if the expected number of patients has been reached (15 patients) in the corresponding group of patients (with lateralized or non-lateralized pa).

Keywords: [68ga]ga-pentixafor positron emission tomography adrenal vein sampling unilateral adrenal secretion